Fusible link.



PATENTED APR. 12, 1904.. F. GRAY. FUSIBLE LINK.

APPLICATION FILED MAR. 15, 1902.

N0 MODEL.

fig

g ml UNITED STATES Patented April 12, 1904.

PATENT OFFICE.

FRANK GRAY, OF CHICAGO, ILLINOIS, ASSIGNOR TO J. J. HOWDEN COMPANY, OF MUSKEGON, MICHIGAN.

FUSIBLE LINK.

SPECIFICATION forming part of Letters Patent No. 756,847, dated April 12, 1904. Application filed March 15, 1902- SerialNo. 98,338. (No model.)

To all whom it may concern.-

Be it known that I, FRANK GRAY, a citizen of the United States of America, and aresident of Chicago, Cook county, Illinois, have invented a certain new and useful Improvement in Fusible Links, of which the following is a specification.

My invention relates to fusible links adapted to hold various devices under tension and constructed to release the devices upon the application of heat, so as to, for example, either close or break an electrical circuit, sound an alarm, or open the sprinkler-head of an automatic fire-extinguisher system.

Generally stated, the object of my invention is to provide a simple and inexpensive fusible link which may be advantageously employed for any of the foregoing purposes.

A special object is to provide a link capable of sustaining a comparatively severe tensile strain.

It is also an object to provide a link which will respond quickly to heat and which will insure the proper operation of the device in connection with which it is employed.

Another object is to provide certain details and features of improvement tending to increase the general efficiency and serviceability of a fusible link of this character.

To the foregoing and other useful ends my invention consists in matters hereinafter set separated as a result of the application of heat.

Fig. 7 is a perspective of a sheet-metal bond for tying the two sections of a link together. Fig. 8 is a view illustrating the application of my improved fusible link to the sprinklerhead of an automatic fire-extinguisher system.

As thus illustrated, my improved thermal or fusible link preferably comprises a pluralthe ready attachment of the link to any device which it may be desired to hold under tension or in a certain normal condition. The linksection A is, it will be observed, also provided with a relatively small opening a, which when the links are in their proper relative positions is adjacent the lapping end of the link-section B. This section B is preferably provided with a lug b, which can be formed by bending back the metal cut out from the opening 6. Also, as shown, the two link-sections are preferably provided with opposing grooves or seats a and 6 adapted to receive a transverselyarranged key C. As a matter of further and special improvement the construction also preferably comprises a sheet-metal bond D, which through the medium of fusible metal or solder serves as a means for tying the two link-sections together. This sheet-m etal bond can be formedwith a relatively broad portion cl, adapted to lie upon and be soldered to the outer surface of the link-section B. The opposite end of the said bond can beformed with relatively narrow portions d, adapted to lie at opposite sides of the link-opening a.

As will be observed, the opposite ends of the sheet-metal bond thus formed are offset or out of line and are connected by the transverse connecting portion cZ As shown in Fig. 5 and also in Figs. 1 and 2, the surfaces of the sheet-metal bond are soldered to the outer surface of the two link-sections, and,

furthermore, the lapping or opposing surfaces of the two link-sections are soldered together.

When in condition for use, the parts of the link are connected together, as is shown in- In this way the solder is practically relieved of all strain. When the solder between the various joints is fused or softened by the applicationof heat, the parts of the link separate in the manner shown in Fig. 6. In this figure it will be seen that the melted or fused solder has permitted the sheet-metal bond D to tilt and allow the two link-sections to separate slightly. The separation is sufficient to permit the key to be disengaged from either one of the two grooves or seats. In thisway the two parts or sections of the link are readily pulled apart or separated.

As previously stated, my improved link can be employed in various connections. For example, it may be employed in connection with the sprinkler-head of an automatic fire-extinguisher system, such as shown in Fig. 8. In this figure the two arms 1 and 2 are subject to the pressure of the tension-screw 3. The arrangement is such that the pressure of the screw tends to separate the two arms. As illustrated, each arm is inserted through one of the link-openings, and when properly adjusted and after the set-screw has been tightened the link is held under considerable tensile strain. In case of fire the heat melts the solder or fusible material of the link, and the two link-sections are then separated or pulled apart by the two arms. This opens the discharge-opening in the sprinkler-head and allows the water to be discharged in the usual well-known manner. The construction of the link is, it will be observed, such as to render it capable of sustaining a comparatively severe pull or tensile strain. This insures against any accidental releasing of the device in connection with which the link may be employed.

As explained,however,the arrangement shown in Fig. 8 is merely illustrative of one of the many purposes for which my invention may be employed.

If desired, a link or tensile-strain-sustaining device such asIhave shown and described may be employed in connection with any device which when released will close an electrical circuit, operate some suitable alarm as aresult of the application of heat to the link, or in any other way automatically perform a useful function.

What I claim as my invention is 1. A fusible link comprisinga couple of lapping sections, one of said sections being provided with a lug or bent portion overhanging the end of the other section, the other section being provided with an opening, a sheet-metal bond having a transverse portion extending through said opening, and suitable solder or other fusible material for binding the parts together.

2. A fusible link comprisingacouple of lapping sections, a transverse key lying between the two sections, one of-said sections being provided with'a projection overhanging the lapping end of the other section, the other section being provided -with an opening, a

' FRANK GRAY.

Witnesses:

ARTHUR F. DURAND, HARRY P.'BAUMGARTN ER. 

